we are running SQL 2005 Ent. x64 in production. The transaction log of one of the databases suddenly grew by 25GB in one hour earlier this morning. I noticed it when I checked the hourly transaction log backup files - it was over 25GB between 9am and 10am. Normally, the transaction log backup file is around 1GB around the same time. The size of transaction log file grew from about 20GB to around 50GB during the same time period. How do I figure out what was going on during that time? What made the log grew that much?